DMG-CPU B
| DMG-CPU B | |
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| Developer: | Nintendo |
| Released: | 1989-04-21 |
| Type: | Chip |
| Channels: | 1.) Pulse Wave |
The DMG-CPU B, also known as the Sharp LR35902 is the primary CPU of the Game Boy. It had a built in audio processing unit (APU) which included a PSG which was designed by Satoru Okada and Hirokazu Tanaka. This PSG was US patent publication number US5095798 A, it was filed on 1990-01-08, published on 1992-03-17, and given application number 07/462,491.
The PSG consists of four channels, two pulse waves, a programmable wave, and a noise channel. Volume envelopes are supported on both square waves and the noise channel. The first square wave supports a frequency sweep, and the programmable wave supports up to 32 4-bit samples. The noise channel supports a frequency range from 2-1,048,576 Hz, and the other three channels support a frequency range of 64-131,072 Hz. The sound chip also has an ambitious feature; it supports stereo sound, but only when the audio jack is used.
An upgraded version of the chip, the CPU-CGB B, would later be utilized in the Game Boy Color. While there were various improvements made to the CPU core, the audio component was unaltered.
Image Gallery
The DMG-CPU B on a Game Boy circuit board.
Back of the chip.
The bare circuitry of the chip.
Emulation Status
Most Game Boy emulators and GBS players can emulate the audio functions of the DMG-CPU B.
Links
- google.com/patents/US5095798 - US patent information.
